The United States force directing the search for weapons of mass destruction in Iraq is pulling out, according to The Washington Post.

The 75th Exploitation Task Force is dismantling its operations for a likely departure in June, says the newspaper, after the group failed to find any biological and chemical weapons.

Members of the team told the newspaper that they no longer expected to find such stocks, and that they had consistently found targets identified by Washington to be inaccurate, or to have been looted and burned.

The force will hand over to a new team, the Iraq Survey Group.

But, according to the Washington Post, the number of weapons experts in the new outfit has been significantly reduced and some units have already sent home as many as a third of their original complement.

"We thought we would be much more gainfully employed, or intensively employed, than we were," said Navy Commander David Beckett of the Defence Threat Reduction Agency.

Evidence 'important'

US President George W Bush and British Prime Minister Tony Blair had used the alleged threat posed by Iraq's suspected weapons of mass destruction as the main justification for waging war.

Correspondents say that while the failure to discover such weapons may not matter to many Americans, in Europe - where many people strongly opposed the war - the issue is likely to become a political one.

Why are we doing any planned targets? We know they're empty

Richard L Gonzales

Last week, the commander of UK forces in the Iraq conflict Air Marshal Brian Burridge said he had "no doubt" that evidence of the weapons would be found.

He accepted that it was "very important" that such proof was uncovered, in order to show the public the concerns that prompted the war were genuine.

However, Army Colonel Richard McPhee, who will close down the task force next month, told the Washington Post if Iraq thought of using such weapons, "there had to have been something to use. And we haven't found it".

"Books will be written on that in the intelligence community for a long time," he added.

Army Colonel Robert Smith, who leads the site assessment teams from the Defense Threat Reduction Agency, said task force leaders no longer "think we're going to find chemical rounds sitting next to a gun." He added, "That's what we came here for, but we're past that."

The UK's dossier on Iraq's banned weapons (Al-Hussein missiles)

US Central Command began the war with a list of 19 top weapons sites - only two remain to be searched.

Another list enumerated 68 top "non-WMD sites," without known links to special weapons but judged to have the potential to offer clues. Of those, the tally at midweek showed 45 surveyed without success.

"Why are we doing any planned targets?" said Army Chief Warrant Officer Richard L Gonzales, leader of Mobile Exploitation Team Alpha, reports the Washington Post.